Originally Posted by mo949
When you say ABL is always working to different degrees, I think we get that, but what we aren't understanding is its influence on the picture being displayed. If the screen hits a low enough brightness level where the ABL logic doesn't need to limit any more brightness, what is its affect(s) on the picture in that scenario?
The best example is the luminance reduction we see viewing hockey games when the camera pans from a darker average scene to one with a lot of bright ice and the luminance drops immediately. This is not to be confused with the arena strobes triggered by professionals' cameras which most find more obnoxious than ABL. Other than this scenario most ABL is hardly noticed except for a few people who are particularly sensitive. Basically, gamma is affected and cannot be well controlled. In calibration, different pattern sizes yield different results along with the question of whether to use these windows patterns on a black background or a changing background to try and keep the APL (average picture level) the same. The bottom line is that there is no correct answer and although many studios and post production houses are still using plasmas, many are switching to LCD and most likely soon to OLED, and we will too.
Meanwhile, plasma is by far the best bang for the buck because of superior black levels, both darkness and the lack of flashlighting and clouding found on edge lit LED LCDs. This gives us better dynamic range (contrast ratio) despite not being as bright on the high end and contrast ratio is the single most important factor in picture quality. You really can't go wrong with a Panasonic ST, GT, VT, or ZT so stick with what you have until OLED becomes affordable.
Also, people talk about the ABL kicking in and skewing the color accuracy at much brighter levels, can you tell us what's happening there?
ABL reduces the luminance of color as well as white. This is in fact part of "accuracy" but does not reduce color saturation as some believe. Personally, I'm insensitive to the change and find it to be no big deal, but that's me. You?